Well I know Petitions work on Bandai Namco, when Dark Souls fans demanded a PC Port or Digimon Fans demanded a new game of the series, then it worked.
But I hope this will help, but I need more voices to be heard, So BN will hear us.
So it's since 4 or 5 years without a "TRUE" Katamari game (Not Tap My Katamari, since some of you guys were hating it for not staying true to the series, I think?)
But I do have an Idea of what BN didn't have. why not Re-Release or Revisit those old games. I think the Original PS2 Games of Katamari (Katamari Damacy and We Love Katamari) will Re-Release for the PS2 Classics to PS4 via PS Store (Remember how you play the Classic GTA PS2 Titles?)
Second/Plus a HD Remaster of 4 Games like Me and my Katamari, Beautiful Katamari, Katamari Forever and Touch My Katamari (PS4 Exclusive Maybe? Your Choice or idea here). And look all the other Games like Crash Bandicoot, The Last of Us, Mario Kart 8 etc. had their Remasters already. Maybe BN will know that remasters might make a good buck for them since other companies do it. Even If Bandai Namco didn't have any new ideas of a new game in the series. why not Bundle them into one instead. Make it happen...
Ask me, if you want. I'm not sure if remasters might be good for you guys. I think demand can help?